Exemplary embodiments of the invention pertain to the art of turbomachines and, more particularly, to a method of establishing wheel space temperature alarms in a turbomachine.
Combustion turbines include a compressor having a plurality of stages that create a compressed airflow and a turbine having a turbine rotor that drives a shaft. During operation, temperatures at the turbine rotor rise significantly. Cooling is provided by directing compressor discharge air into a wheel space that extends about the turbine rotor. Wheel space temperature is maintained at a material limit between compressor discharge temperature and hot gas path temperature. In the event that the wheel space temperature exceeds the material limit, an alarm is sounded to indicate an over temperature condition. When the material limit is exceeded, the turbomachine is shut down and bore plugs are removed to provide additional cooling flow. Various factors can affect compressor discharge air temperature. For example, as ambient inlet air temperature rises, compressor discharge air rises. Conventional wheel space temperature monitors establish a single non-flexible material limit that does not take into account changes in ambient temperature or operating parameters.